• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2743-2750
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• 2011

Lanthanide(III)-cored complex as a wavelength conversion material has been successfully designed and synthesized for highly efficient dye-sensitized solar cells, for the first time, since light with a short wavelength has not been effectively used for generating electric power owing to the limited absorption of these DSSCs in the UV region. A black dye (BD) was chosen and used as a sensitizer, because BD has a relatively weak light absorption at shorter wavelengths. The overall conversion efficiency of the BD/WCM device was remarkably increased, even with the relatively small amount of WCM added to the device. The enhancement in $V_{oc}$ by WCM, like DCA, could be correlated with the suppression of electron recombination between the injected electrons and $I_3{^-}$ ions. Furthermore, the short-circuit current density was significantly increased by WCM with a strong UV light-harvesting effect. The energy transfer from the Eu(III)-cored complex to the $TiO_2$ film occurred via the dye, so the number of electrons injected into the $TiO_2$ surface increased, i.e., the short-circuit current density was increased. As a result, BD/WCM-sensitized solar cells exhibit superior device performance with the enhanced conversion efficiency by a factor of 1.22 under AM 1.5 sunlight: The photovoltaic performance of the BD/WCM-based DSSC exhibited remarkably high values, $J_{sc}$ of 17.72 mA/$cm^2$, $V_{oc}$ of 720 mV, and a conversion efficiency of 9.28% at 100 mW $cm^{-2}$, compared to a standard DSSC with $J_{sc}$ of 15.53 mA/$cm^2$, $V_{oc}$ of 689 mV, and a conversion efficiency of 7.58% at 100 mW $cm^{-2}$. Therefore, the Eu(III)-cored complex is a promising candidate as a new wavelength conversion coadsorbent for highly efficient dye-sensitized solar cells to improve UV light harvesting through energy transfer processes. The abstract should be a single paragraph which summaries the content of the article.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.383-390
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• 2020

Blue light is a blue-based light existing at a wavelength between 380 and 450 nm, and it has been reported that it induces active oxygen and causes aging, and accordingly, interest in the blue light blocking effect is increasing. In this study, the effects of the polarity of oil, viscosity of the formulation, type of emulsifier, emulsified particles, and inorganic UV blocking agents on the blue light blocking effect in UV blocking products were investigated. As a result, it was confirmed that the blue light blocking rate increased as the polarity of the oil became similar to that of the organic UV blocker, and the higher the viscosity of the formulation, the higher the blue light blocking rate. The types of emulsifiers and emulsified particles had little effect on the blue light blocking effect, and the presence of inorganic UV blocking agents was found to be one of the factors that greatly influenced the blue light blocking rate. These results can effectively increase the efficiency of blocking blue light, and may be used in the development of blue light blocking products and formulation research in the future.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.293-294
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• 2009

The spectral responsivity of solar cells has been measured under high background irradiance using an LED-based differential spectral responsivity Comparator (DSR-C). The comparator developed is fully automated and has some advantages: It does not need a chopper to modulate the light. Unlike the conventional method, it does not require a monochromator to select wavelength. It covers a wavelength range up to 1200 nm. The wavelength range of the comparator is limited by the spectral power distribution of the LEDs and the spectral responsivity of the standard detector. An active temperature control was utilized to meet the specified standard conditions of solar cell test. This work shows the effect of different levels of background irradiance on the spectral responsivity and the importance of same background irradiance for solar cell test as specified by the corresponding standard.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.267-271
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• 2009

The aim of this study is to evaluate wavelength dependence for laser-assisted lipolysis using a mathematical simulation. In this study, a Monte Carlo simulation was performed to simulate light transport in fat and dermal tissue with 3 different laser wavelengths (${\lambda}\;=\;1064\;nm$, 1320 nm, and 1444 nm) that are currently used in clinic settings for laser-assisted lipolysis. The relative rates of heat generation versus penetration depth showed that the greatest amount of heat generation was seen in the tissues at ${\lambda}\;=\;1444\;nm$. This Monte Carlo simulation may help lend insight into the thermal events occurring inside the fat and dermal tissue during laser-assisted lipolysis.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.310-315
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• 2003

The dyeing of cotton fabric with Forsythia koreana NAKAI was investigated. The colorant was extracted with methanol under various concentrations of dyestuffs at $40^\circ{C}$ and $76^\circ{C}$. UV-VIS spectrum was obtained to find the maximum wavelength of colorant. Cotton fabrics were dyed at different temperatures, mordants, in pre and post mordanting methods. The maximum wavelength of spectrum were 390nm, 410nm, 440nm. The highest K/S value was showed at 100% dye concentration, extracted at $76^\circ{C}$ and dyed at $80^\circ{C}$. The mordant effect was not good in the K/S values. The light fastness was increased at Fe-pre mordant and Cr, Fe-post mordant.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.107-110
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• 2001

In order to estimate the UV-A line's cut efficiency it lens, it was measured the light transmittance in the 320~400nm wavelength regions. We obtained the area to integrate the light transmittance of standard CR-39 and sample in the 320~400nm wavelength regions and established ${\alpha}$, ${\beta}$ of UV-A line's cut efficiency by contrast its area. We obtained the absolute cut efficiency ${\alpha}$ CR=0.59 value of CR-39 Lens, and if ${\alpha}$ was the absolute cut efficiency value of the lens to estimate UV-A cut effect, the relative cut efficiency ${\beta}$ was $1.69{\alpha}$. It was obtained the absolute and the relative UV exclusion index through each $a=(1-{\alpha}){\times}100%$, $b=(1-{\beta}){\times}100%$.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.120-133
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• 2008

The purpose of this study is to analysis types of light and to find the characteristics of light in contemporary fashion design. In a scientific context, light is electromagnetic radiation of a wavelength that has the characteristics of straightness, reflection, refraction, scattering and diffraction. But in philosophical speculations, light has been used as a metaphor of 'being', 'to-be' or 'enlightenment.' And through the ages, people have tried to represent and apply the light into plastic art like painting and architecture. The types of light in fashion design was categorized as those; reflective light from the surface of clothing which is the result of interaction between illumination and material, representative light as the pattern of light or light effect such as sun or its rays and optical or psychedelic patterns, luminescent light from light emitting material like phosphorescence or LED which combines into fashion design, projective light from a medium to reveal virtual patterns on the surface or a fashion design itself using holography. These lights in fashion design can be considered as reflection of emphasis of sexuality, longing for fantasy and mystique, visualization of interaction and communication and groping for the play.

• Korean Journal of Microbiology
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• v.6 no.4
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• pp.122-130
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• 1968

Action of various wavelengths of visible light on ultraviolet-radiation damage to haploid yeast cells, Saccharomyces cerevisiae 23971, was studied. The results were obtained on the basis of the survival and respiration rates by pre- and post-illuminations of various wavelengths before and after U.V.-irradiations on the yeast cells. Among the wavelengths tested, 635 $m{\mu}$, 429 $m{\mu}$ and white light which caused increase of respiration in pre-treatment alone, induced less resistance to the U. V.-damage than in the control, in both pre- and U.V.-treatment. On the contrary, such wavelengths as 574 $m{\mu}$and 530 $m{\mu}$, showing a weak effect on respiration in pre-treatment increased the susceptability to U.V.-radiation. Photoinactivation was generally obtained by both pre- and post- illuminations along with U.V.-treatment. At 635 $m{\mu}$ the PI rate was the lowest and also a low PI rate was shown at 429 $m{\mu}$. But 429 $m{\mu}$, in the post-treatment of the yeast cells pre-treated by the white light and the darkness respectively, showed the highest PI rate. In both pre- and post- treatment of 574, 530 and 473 $m{\mu}$,the PI rates were high to the same degree. Post-treatments of the wavelengths on U.V.-treated yeasts incubated rather under the white light than the darkness induced lower PI rate. It is assumed that there are great differences in action even of the same wavelength, depending upon the various combination of pre- and post-treatments, and that, moreover, the action of various wavelengths of visible light on U.V.-damage on the cells are concerned with the doses and dose rates of U.V. and visible lights. These observations led to an interpretation that each wavelength of visible light might exert distinctively different effects oil U. V.-damage, mainly causing the inhibition or stimulation of enzymes in the yeast cells.

• Journal of Conservation Science
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• v.36 no.4
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• pp.236-243
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• 2020

In this study, an accelerated aging experiment for fabric and paper was conducted using two light emitting diode(LED) sources with different wavelength characteristics, and the discoloration under each lighting type was examined. Hanji(Korean traditional paper) and related textiles showed more discoloration under blue LEDs, while the blue wool standard showed more discoloration under white LEDs. This, indicated that the deterioration varied depending on the sample color. The the effect of the light source on artifact deterioration was primarily related to the total radiation flux(expressed in mill watts), rather than the total luminous flux(expressed in lumens). In addition, the discoloration of the investigated artifacts was dependent on the color rendering of the lighting.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.565-568
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• 2008

In this study, a blue-emitting $Sr_2MgSi_2O_7:Eu^{2+}$ (SMS) phosphor for white light-emitting diodes is reported. Through transition of $4f{\rightarrow}5d$ in $Eu^{2+}$, SMS showed a strong blue emission under UV excitation. Additionally, the variation of emission wavelength of SMS is explained by crystal field effect and is supported by rietveld refinement.